将函数输出保存到参数中命名的变量中 [英] Saving function output into a variable named in an argument

问题描述

我有一个有趣的问题，我似乎找不到答案。我正在创建一个简单的应用程序，将帮助我的开发部门自动启动Docker容器与NginX和配置文件。我的问题是，由于某种原因，我无法获取bash脚本来存储文件夹的名称，同时扫描目录。这是一个非常简单的例子，我在说什么....

 ＃！/ bin / bash 
 
 getFolder（）{
 local __myResultFolder = $ 1 
本地文件夹
 for d in * /;做
 $ folder = $ d 
 done 
 __myResultFolder = $ folder 
 return $ folder 
} 
 
 getFolder FOLDER 
 
 echo使用文件夹：$ FOLDER
  

然后我将这个简单的脚本保存为folder_test.sh并将它放在只有一个文件夹的文件夹中，将所有者更改为我，并给予正确的权限。但是，当我运行脚本时，我不断收到错误...

  ./ folder_test.sh：8 ./folder_test。 sh：= test_folder /：找不到
  

我已经尝试将 $文件夹= $ d 部分在不同类型的报价单，但没有任何作用。我试过 $ folder ='$ d'， $ folder =`$ d` code> $ folder =$ d但没有一个工作。驾驶我疯狂，任何帮助将不胜感激。谢谢。

解决方案

罪魁祸首是

  $ folder = $ d 
  

这是将文件夹名称与一个 = 签名之前，尝试以该名称扩展它，即字面上将名称 = test_folder / 视为可执行文件在shell下运行，但没有找到该名称的文件。将其更改为

  folder = $ d 
  

另外， bash 函数的返回值只限于整数类型，您不能向调用函数发送字符串。如果您想在 $ folder 为空的调用函数发送一个非零返回码，您可以添加一行

[pre> 如果[-z$ folder];然后返回1;否则返回0; fi


（或）如果要从函数返回字符串值，请不要使用 return ，只需执行 echo 的名称，并使用命令替换功能名称，即

  getFolder（）{
 local __myResultFolder = $ 1 
本地文件夹
 for d in * /;做
文件夹= $ d 
完成
 __myResultFolder = $文件夹
回显$文件夹
} 
 
 folderName = $（getFolder FOLDER ）
 echo$ folderName
  

I have an interesting problem that I can't seem to find the answer for. I am creating a simple app that will help my dev department auto launch docker containers with NginX and config files. My problem is, for some reason I can't get the bash script to store the name of a folder, while scanning the directory. Here is an extremely simple example of what I am talking about....

#!/bin/bash

getFolder() {
    local __myResultFolder=$1
    local folder
    for d in */ ; do
        $folder=$d
    done
    __myResultFolder=$folder
    return $folder
}

getFolder FOLDER

echo "Using folder: $FOLDER"

I then save that simple script as folder_test.sh and put it in a folder where there is only one folder, change owner to me, and give it correct permissions. However, when I run the script I keep getting the error...

./folder_test.sh: 8 ./folder_test.sh: =test_folder/: not found

I have tried putting the $folder=$d part in different types of quotes, but nothing works. I have tried $folder="'"$d"'", $folder=`$d`, $folder="$d" but none of it works. Driving me insane, any help would be greatly appreciated. Thank you.

解决方案

The culprit is the line

$folder=$d

which is treating the folder names to stored with a = sign before and tried to expand it in that name i.e. literally treats the name =test_folder/ as an executable to be run under shell but does not find a file of that name. Change it to

folder=$d

Also, bash functions' return value is only restricted to integer types and you cannot send a string to the calling function. If you wanted to send a non-zero return code to the calling function on $folder being empty you could add a line

if [ -z "$folder" ]; then return 1; else return 0; fi

(or) if you want to return a string value from the function, do not use return, just do echo of the name and use command-substitution with the function name, i.e.

getFolder() {
    local __myResultFolder=$1
    local folder
    for d in */ ; do
        folder=$d
    done
    __myResultFolder=$folder
    echo "$folder"
}

folderName=$(getFolder FOLDER)
echo "$folderName"

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